Caterpillar belt trains



12, 1965 E. DAVENPORT ETAL 3,211,305

CATERPILLAR BELT TRAINS Filed Sept. 30, 1965 2 Sheets-Sheet l Awavmes1965 E. DAVENPORT ETAL 3,211,305

CATERPILLAR BELT TRAINS Filed Sept. 50, 1963 2 Sheets- Sheet 2 Avwwms fpp DAVE/YPaRT FIeA/v/e fl/AMS Jrs new:

United States Patent 3,211,395 CATERPILLAR BELT TRAINS EverardDavenport, Uxtord Hotel, Oxford Road, Rosebanlt, and Frank E. Stevens,104 Braekenhurst, (Iorlett Drive, Illovo, both of Johannesburg,Transvaal, Republie of South Africa Filed Sept. 30, 1963, Ser. No.312,665 Claims priority, application Republic of South Africa, Get. 2,1962, 4,169/62; Mar. 1, 1963, 861/63 11 Claims. (Ill. 214-452) Thisinvention relates to caterpillar belt trains.

A caterpillar belt train consists in a series of pans supported on aseries of undercarriage units usually fitted with rail wheels. Theundercarriage units are connected for traction in either direction bymeans allowing a wide degree of movement between the pans about the axisof traction as well as around corners. The bearing surfaces of the pansare connected by means of flexible membranes usually made of rubberconveyor belt material.

In use the pans are loaded while they are in the erect position. Forunloading the train is moved over inclined rails which cause individualundercarriage units with their pans to tilt to discharge their burden.With relatively flat pans the usual tilting angle is already as high as70.

However such relatively flat pans have a low capacity per unit length.Attempts have been made to increase the capacity of the train byincreasing the height of the pans so that they are almostsemi-cylindrical in shape. In such a case the tilting angle fordischarge is 135, which is almost a complete turn-about. Even then allmaterial is not always discharged.

The invention seeks to retain the advantages of conventional relativelyfiat belt trains and yet increases its capacity. In some embodiments theinvention also dispenses with tilting of the undercarriage units duringdischarge operations.

According to the invention a pair of parallel upstanding walls projectfrom the edges of the pans and are ar ranged to flex over the regions ofthe membranes, with at least the first wall of the pair resting freelyon the pans and being capable of moving along a different trajectory tothe train during discharge operations.

Further according to the invention each pan is surmounted by arectangular rigid box that is open top and bottom and the boxes areconnected together by flexible elements over the membranes, two opposedsides of each box constituting parts of the wall. Sides that constitutepart of the second wall are hingedly connected to the pans below them.

As appears from the following description this basic construction issusceptible of a number of modifications.

The invention is further discussed with reference to the accompanyingdrawings, in which:

FIGURE 1 is a view of a part undercarriage unit of one embodiment of theinvention,

FIGURE 2 is a perspective view of part of the embodiment illustrated inFIGURE 1 with undercarriage details omitted,

FIGURES 3 to 5 are diagrammatic views illustrating successive stagesduring the discharge of the embodiment of FIGURES 1 and 2,

3,2ll,3% Patented Get. 12, 1955 FIGURE 6 is a view similar to FIGURE 1of a further embodiment,

FIGURE 7 is a diagrammatic view illustrating the method of dischargingthe embodiment of FIGURE 6,

FIGURE 8 is a View similar to FIGURE 7 showing another method, and

FIGURE 9 is a diagrammatic plan view of the rail installation used inFIGURE 8.

The embodiment illustrated in FIGURES 1 and 2 comprises known structurewhich may take any one of a variety of known forms and the structureprovided by the invention.

Dealing firstly with the known structure it consists of a plurality ofundercarriage units having horizontal axles 9 and wheels It). Theundercarriage units have cradles 111 on which there rest pans I2,usually of sheet metal. The undercarriage units may or may not have acentral spine 13, but preferably has such spine, and are joined togetherby universal joint structures which permit consecutive undercarriageunits to move relatively to one another in any required direction as thetrain follows the grade and contour of a track.

The pans 12 are connected by flexible membranes 14 usually of rubberwhich are slightly longer than the gap between pans, also in a knownmanner.

Provided that suitable precautions are taken during discharge, thewheels 10 need not necessarily be rail wheels, but they preferably arerail wheels.

The structure provided by the invention consists in a rectangular rigidbox that is open top and bottom and surmounts each pan 12. One side wall15 of each box is hinged to its pan 12 at 16, the other side wall 17resting freely on the pan 12.

The ends 18 of the boxes going across the train serve as struts to thesides 15 and I7 and need not be the same width as the sides. The ends 18at abutting ends of boxes are vertically staggered so that large rocksor the like that fall in the gaps between the boxes may be moreconveniently accommodated.

The boxes are connected by flexible elements 19, usually of rubber,which are slightly longer than the distance between boxes when the trainis straight. The elements 1'9 have downwardly hanging flaps 20 that sealon the membranes 14.

The side 17 of each box is provided with a guide roller 21 adapted toco-operate with a rail 22 provided at the discharge station.

Apart from the rail 22 the discharge station for this embodiment is thesame as the known discharge station at which the train is twistedsection by section to discharge its burden. The rail 22 serves to guidethe edges of the sides 17 so that the boxes follow a differenttrajectory to the pans If. and, for that matter, the undercarriageunits.

Successive stages in a discharge operation are illustrated in FIGURES 3to 5, where FIGURE 3 illustrates the commencement of the dischargeoperation, FIGURE 4 an intermediate stage and FIGURE 5 the final stageof unburdening. Of course, the train returns to its normal runningposition through similar stages in the reverse order.

The discharge operation discussed above has some disadvantages. Firstlytraflic other than belt trains cannot enter the station or pass through.Secondly the overall distance required for the discharge operation isfairly long.

To obviate these disadvantages to some extent the invention provides theembodiment of FIGURE 6. In this case each pan 12 is hinged to theundercarriage unit at 23 and the side 17 is provided with a hookformation 24.

The embodiment of FIGURE 6 is discharged while the train is stationaryat a tipping station which may be of the kind used with ordinary sidedischarge trucks.

A tipping operation is illustrated in FIGURE 7. Here a grab structureengages with the hooks 24 and pulls the boxes sideways and upwardlyuntil the train reaches the position shown. The grab structure 30 isconveniently actuated by a suitable hydraulic ram.

If the undercarriage units are not heavy enough to remain horizontalunder self-weight during discharge, the far side of the train should beanchored to the rail bed. Thus the undercarriage could be provided withformations 26 that engage with complemental hold down rail sectionswithin the area of the discharge station 25 on the rail bed asillustrated in FIGURE 6.

The fact that the train has to be stationary during discharge operationsmay be a disadvantage in high speed operations. In such a case theembodiment of FIGURE 6 may be provided with rollers 21 as in FIGURE 1.This is shown diagrammatically in FIGURES 8 and 9. In FIGURE 8 thenormal position of the train is shown in full while the dischargeposition of the pans and boxes is shown in chain line. The approximatecontour of the guide rail 27 used in this case is shown in plan in FIG-URE 9. The rail bends sideways and upwardly to reach the chain lineposition in FIGURE 8.

In this embodiment also means for holding down the undercarriage units(as in FIGURE 6) may be necessary.

In both of the embodiments of FIGURES 6 and 7 and 8 and 9 the track areais entirely clear so that normal traffic may pass the discharge stationand locomotives with overhead trolleys may be used.

Thus by the addition of the boxes on the train the capacity of aconventional Caterpillar belt-train has been increased. Of course,axles, bearings and traction parts should be strong enough to carry theextra duty.

We claim:

1. In a Caterpillar belt train, comprising a plurality of universallyarticulated, wheeled undercarriage units, a plurality of troughed panscarried by the undercarriage units and troughed flexible membranesjoining adjacent pans, the pans and the membranes constituting anelongated load-carrying surface, the improvement of a pair of parallelupstanding walls projecting from the edges of the pans, having rigidportions over the pans and flexible portions over the regions of themembranes and extending the length of the load-carrying surface, with atleast the first wall of the pair resting freely on the pans and beingcapable of being lifted off the pans during discharge operations, andformations on the first wall adapted to engage with lifting gear duringdischarge operations.

2. The train claimed in claim 1 in which the rigid portions of the wallsare connected by braces spanning the width of the pans and spacing thewalls in parallel relationship.

3. The train claimed in claim 2 in which the rigid portions of thesecond walls are hinged to the pans below them.

4. The train claimed in claim 3 in which the formations on the firstwall are guide rollers adapted to engage with a guide rail duringdischarge operations.

5. The train claimed in claim 3 in which each pan is hinged to anundercarriage unit supporting it at that side that is under the firstwall.

6. The train claimed in claim in which the formations on the first wallare guide rollers adapted to engage with a guide rail during dischargeoperations.

7. The train claimed in claim 5 in which the formations on the firstwall are hook formations adapted to d be engaged by lifting gear andpulled transversely to the length of the wall by the lifting gear.

8. The combination of a caterpillar belt train, comprising a pluralityof universally articulated, wheeled undercarriage units, a plurality oftroughed pans carried by the undercarriage units, troughed flexiblemembranes joining adjacent pans, the pans and the membranes constitutingan elongated load-carrying surface, a pair of parallel upstanding wallsprojecting from the edges of the pans, having rigid portions over thepans and flexible portions over the regions of the membranes andextending the length of the load-carrying surface, with at least thefirst wall of the pair resting freely on the pans and being capable ofbeing lifted off the pans, and guide formations on the first wall; and adischarge station including lifting gear adapted to engage with theguide formations and during relative movement of the undercarriage unitsand the lifting gear to lift the first wall oil the pans underlying it.

9. The combination of a caterpillar belt train, comprising a pluralityof universally articulated, wheeled undercarriage units, a plurality oftroughed pans carried by the undercarriage units, troughed flexiblemembranes joining adjacent pans, the pans and the membranes constitutingan elongated load-carrying surface, a pair of parallel upstanding wallsprojecting from the edges of the pans, having rigid portions over thepans and flexible portions over the regions of the membranes andextending the length of the load-carrying surface, with at least thefirst wall of the pair resting freely on the pans and being capable ofbeing lifted off the pans, which pans are fixed to the undercarriageunits, and guide rollers on the first wall; and a discharge stationincluding rails engaged with the wheels of the undercarriage units andadapted to tilt the train to discharge its burden over the edge of theload-carrying surface underlying the first wall, and a guide railadapted to engage the guide rollers and to cause the first wall to movesideways and upwardly relatively to the edge over which the burden isdischarged.

10. The combination of a caterpillar belt train, comprising a pluralityof universally articulated, wheeled undercarriage units, a plurality oftroughed pans carried by the undercarriage units, troughed flexiblemembranes joining adjacent pans, the pans and the membranes constitutingan elongated load-carrying surface, a pair of parallel upstanding wallsprojecting from the edges of the pans, having rigid portions over thepans and flexible portions over the regions of the membranes andextending the length of the load-carrying surface, with at least thefirst wall of the pair resting freely on the pans and being capable ofbeing lifted off the pans, each of which pans is hinged to anundercarriage unit supporting it at that side that is under the firstwall, and guide rollers on the first wall; and a discharge stationincluding a guide rail adapted to engage with the guide rollers andguide them sideways and upwardly relatively to the direction of movementof the undercarriage units, such sideways and upward movement causingthe pans to tilt about their undercarriage units.

11. The combination of a caterpillar belt train, comprising a pluralityof universally articulated, wheeled undercarriage units, a plurality oftroughed pans carried by the undercarriage units, troughed flexiblemembranes joining adjacent pans, the pans and the membranes constitutingan elongated load-carrying surface, a pair of parallel upstanding wallsprojecting from the edges of the pans, having rigid portions over thepans and flexible portions over the regions of the membranes andextending the length of the load-carrying surface, with at least thefirst wall of the pair resting freely on the pans and being capable ofbeing lifted off the pans, each of which pans is hinged to anundercarriage unit supporting it at that side that is under the firstwall, and hook formations on the first wall; and a discharge stationincluding means 5 6 to engage with the hook formations and to pull themside- 2,042,266 5/36 McCallen 214-58 X Ways and upwardly, while thetrain is stationary, so as 2,623,651 12/52 Vial. to cause the pans totilt about the undercarriage units. 2,719,636 10/55 Berg 21463 2,979,1844/61 Becker et a1 198-109 References Cited by the Examiner 5 UNITEDSTATES PATENTS 500 852 S Q PATENTS 280,904 7/83 Boyer 214-64 5 61,893,633 1/ 33 Peterson et a1. GERALD M. FORLENZA, Pnimary Examiner.

1. IN A CATERPILLAR BELT TRAIN, COMPRISING A PLURALITY OF UNIVERSALLYARTICULATED, WHEELED UNDERCARRIAGE UNITS, A PLURALITY OF TROUGHED PANSCARRIED BY THE UNDERCARRIAGE UNITS AND TROUGHED FLEXIBLE MEMBRANESJOINING ADJACENT PANS, THE PANS AND THE MEMBRANES CONSTITUTING ANELONGRATED LOAD-CARRYING SURFACES, THE IMPROVEMENT OF A PAIR OF PARALLELUPSTANDING WALLS PROJECTING FROM THE EDGES OF THE PANS, HAVING RIGIDPORTIONS OVER THE PANS AND FLEXIBLE PORTIONS OVERF THE REGIONS OF THEMEMBRANES AND EXTENDING THE